Single-phase alternating-current system of distribution.



PATENTED JAN. 17, 1905.

P M. LINGGLN. SINGLE PHASE ALTERNATING CURRENT SYSTEM OF DISTRIBUTION.

APPLICATION FILED MAY 3.1904.

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/ ATIORNEY No. 780,048. Patented January 17, 1905.

UNITED STATES PATENT OFFIC PAUL M. LINCOLN, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO EST- INGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SINGLE-PHASE ALTERNATlNG-CURRENT SYSTEM OF DISTRIBUTION.

SPECIFICATION forming part of Letters Patent No. 780,048, dated January 17, 1905.

Application filed May 3, 1904. Serial No. 206,187.

T all 107107 it y @mwern: I of an alternating-current generator 4:, the

Be it known that I, PAUL M. L1NooLN,a citiother terminal of which is shown as connected 5 zen of the United States, and a resident of to ground by means of a conductor 5. The

Pittsburg, in the county of Allegheny and other end terminal 6 of the transformer 1 is 5 State of Pennsylvania, have invented a new connected to one conductor 7 of the circuit for and useful Improvement inaSingle-Phase Alsupplying the motors S, the other conductor ternating-Current System of Distribution, of 9 of the motor-circuit being connected to a which the following is a specification. point 10 in the winding 1 which will insure My invention relates to systems of distributhe desired difference of potential between the 10 tion for single-phase alternating-current enmotor-terminals. A point 11 in the winding ergy; and it has for its object to provideasys- 1 between the points 6 and 10 is connected tem in which energy may be transmitted at to the grounded conductor 5. It the system high voltages and delivered through voltageis employed for the operation of railway-moregulating apparatus to translating devices tors, the conductor 5 might be the track or 5 at lower voltages and in which the differences the grounded portion of the circuit.

of potential between the grounded conductor The conductor 9 of the motor-circuit infrom the source of energy and the respective eludes the secondary winding 12-of a series 5 terminals of the translating devices are retransformer18. Theterminalsof theprimary duced to safe and limited values. winding 14. of the series transformer 13 may 20 It has been proposed to operate by means be respectively and reversibly connected to of alternating-current energy motors of the the terminal of the secondary winding 12 that commutator type of construction having seis adjacent to the motors 8 and to a desired 7 rice-connected armature and field magnet point in the main transformer-winding 1 by windings, such motors being similar in many means of a reversing-switch 15. The trans- 5 respects to ordinary direct-current motors, former-winding 1 may be provided with a and various systems have been devised for number of spaced leads 16, and a switch-arm transmitting energy at high voltages and sup- 17 be-employed in connection therewith to vary plying it at variable low voltages to motors the point of connection of the winding 1 1 with at the points of consumption. In one system the winding 1.

3 for this purpose with which I am acquainted It is to be understood that the voltage-regthe difference of potential between one termiulating apparatus may be varied considerably nal of the motors and the grounded conductor from what is herein shown and described, is the same as the potential difference between since it forms no part of my present inventhe motor-terminals, whereas in the system tion except in the sense and to the extent that 35 comprising my present invention the diflerit constitutes a desirable and useful feature of ences of potential between the respective mothe system as a whole. tor-terminals and the grounded conductor are In order to reduce the potential difference 5 only one-half that between the motor-termibetween the terminals of the motors Sand the nals. I/Vith this arrangement the stresses on grounded conductor 5 to approximately one- 4 the insulation and the dangers incident to the half the maximum dilierence of potential beoperation or repair of the motors are materitween the terminals of the motors, the point ally reduced. 11 in the main transformer-winding 1, which 9 In the accompanying drawing the single iigis connected with the conductor 5, will gen- 5 are is a diagrammatic view of a system of diserally be located somewhat nearer the point 45 tribution embodying my invention. 10, to which the secondary winding 12 of the My system comprises a main transformerseires transformer 13 is connected, than to the winding 1, having one end terminal 2 connectterminal (3, though it is obviously practicable ed, by means of a conductor 3, to one terminal to vary the location of the point 11 from what is shown in the drawing without forfeiting the substantial advantages of the invention. The point 10 is so chosen that when the voltage in the winding 12 is added to the voltage supplied to the motors by the portion of the main transformer-winding 1 between the terminal 6 and the point 10 the full potential is supplied to the motors 8, and so that when the current in the winding 12 is subtracted from that supplied by the portion of the winding between the terminal 6 and the point 10 of the main transformer-winding 1 the lowest starting voltage is supplied to the motors 8.

While I have shown two motors connected in parallel between the conductors 7 and 9, it would of course be feasible to employ a single translating device only or several translating devices, whether motors or other electrical apparatus, and to connect them either in se ries or in parallel, as might be desired.

1 claim as my invention 1. The combination with one or more translating devices and a source of alternating-cur rent energy of higher voltage than that supplied to the said devices, of a transformerwinding having one end terminal and an intermediate point connected to said source and having its other end terminal and another intermediate point respectively connected to the terminals of the translating devices, and means for regulating the voltage supplied to said translating devices.

2. The combination with a source of alternating-current energy and a transformerwinding having one terminal and a point intermediate its terminals respectively connected to said source, of one or more translating de-- vices the terminals of which are respectively connected to the other terminal of said transformer-winding and to a point intermediate its terminals, and means for regulating the voltage supplied to said devices.

3. The combination with a source of alternatingcurrent energy and a transformerwinding having one terminal and an intermediate point respectively connected to said source, of one or more translating devices the terminals of which are respectively connected to the other terminal of said transformerwinding and to an intermediate point therein which is more remote from said last-named terminal than the intermediate connection thereof with the source of energy.

4:. The combination with a source of alternatingcurrent energy and a transformerwinding having one terminal and. an intermediate point respectively connected to said source, of one or more translating devices the terminals of which are respectively connected to the other terminal of said transformerwinding and to an intermediate point therein which is approximately the same distance from the intermediate connection with the source of energy as said connection is from the terminal of the transformer-winding which is connected to the translating devices.

5. The combination with a source of alternating current energy and a transformerwinding having one terminal and an intermediate point respectively connected to said source, 01" one or more translatingdevices the terminals of which are respectively connected. to the other terminal of said transformerwinding and to an intermediate point therein the distance of which from the last-named terminal of the transformer-winding is approximately double that of the point having intermediate connection with the source of energy.

6. The combination with a source of alternatingcurrent energy and a transformerwinding having one terminal and an intermediate point respectively connected to said source, of one or more translating devices the terminals of which are respectively connected to the other terminal of said transformerwinding and to an intermediate point therein such that the point of connection of the source of energy with the transformer-winding which is intermediate its terminals lies between the points of connection of said winding with the translating devices.

7. The combination with a source of alternatingcurrent energy and a transformerwinding having one terminal and an intermediate point respectively connected to said source, of one or more translating devices the terminals of which are respectively connected to the other terminal of said transformerwinding and to an intermediate point therein such that the point of connection of the source with the transformer-winding which is intermediate its terminals lies approximately mid way between the terminal connections of the translating devices therewith.

8. The combination with a source of alternating-current energy and a transformerwinding having one terminal and an intermediate point respectively connected to said source, of one or more translating devices the terminals of which are respectively connected to the other terminal of said transformerwinding and to an intermediate point therein such that the difference of potential between the terminals of the said devices shall be approximately double that between the terminal of the transformer-winding which is connected to the said devices and the intermediate point of connection with the source of energy.

9. The combination with a source of alternating current energy and a transformerwinding having one terminal and an intermediate point respectively connected to said source, of one or more translating devices the terminals of which are respectively connected to the other terminal of said transformerwinding and to an intermediate point therein such that the differences of potential between the respective terminals of the said devices and the intermediate connection in the transformer-winding shall be less than that between the terminals of the said devices.

10. The combination with a source of supply of alternating-current energy and a main transformer-winding having one terminal and a point intermediate its terminals respectively connected to said source, of one or more motors having a terminal or terminals connected to the free terminal of the main transformerwinding, and voltage-regulating apparatus comprising primary and secondary windings J. C. Monsn, BIRNEY HINEs. 

